Depth of field

Visitors to farm shows and precision agriculture events in California have already noticed the trend. More companies are offering specialized crop and land management tools based on customized satellite photos. Will these services make it to the Corn Belt? We talked to a farm manager, some company reps and experts in the field of remote sensing to find out.

Sometimes a major decision requires that you step back to take a fresh look. Back way up, say several hundred miles above the Earth, and you can't help but see things differently.

That's what Cannon Michael, a business operations manager for Bowles Farming in Los Banos, CA, found out. His 12,000-acre spread was a big challenge to monitor, so Michael hoped photos taken from space might provide a fast way to recognize field problems and evaluate production options. Demonstrations he'd seen at farm shows and precision ag events looked promising.

Skeptical, yet hopeful, Michael decided to put the technology to the test in April 2002. He'd noticed that 45 acres within a 141-acre field were producing poor yields due to leakage from an irrigation canal. The initial proposed solution was expensive — install tile along the entire length of the canal to provide adequate drainage and divert excess water. This would have cost $127,000 for the purchase of 9,700 ft. of tile and two pumps.

DigitalGlobe, one of the pioneering companies that provide satellite imagery products for precision farming, got Michael's call. The company's customized AgroWatch maps revealed a pleasant surprise. The total drainage-affected area was less than half of what he initially anticipated — 4,250 rather than 9,700 ft.

Needing only 4,250 ft. of tile and one pump instead of two saved the farm $69,000 on materials alone. The anticipated revenue increase on crop yield is expected to be $17,150 after the first year.

“Satellite imagery saved our farm thousands of dollars,” Michael says. “The AgroWatch Green Vegetation Maps were key to identifying specific problem areas and are also now part of our strategy for increasing yields, allowing us to make better long-term farming decisions.” For Michael, the proof of the technology's value is in the money he saved.

Ag satellite renaissance

It's not just déjà vu if you think you've heard Michael's story, or one like it, before. The first Landsat spacecraft looked down at the Earth on July 23, 1972. The government and a few commercial satellite ventures that never got off the ground promised great financial benefits for agriculture. But claims that satellite photos could help farmers predict diseases, nitrogen deficiencies and other crop stresses proved premature. As a result, most farmers discounted the technology as just another pie-in-the-sky dream.

Now, after 30 years, farmers such as Michael are starting to see some benefits. Satellites are making better images, and the technology and computing power to use the data for agricultural purposes finally exist.

Still in the early stages of business development, DigitalGlobe is one company now building a network of consultants and ag retailers to bring its ready-to-use imagery products to growers throughout the country.

Unlike many of its competitors, which rely mostly on access to government Landsat photos and aerial photos taken from airplanes, DigitalGlobe has its own satellite called QuickBird. The company also acquired exclusive access for agriculture and crop insurance to all North American images taken by Spot Image Corporation, part of the Spot World Group (SWG) with headquarters in Toulouse, France.

SWG operates a constellation of three medium- and high-resolution satellites and a network of receiving stations and processing centers. It is the oldest commercial satellite imaging company, having launched its first satellite in 1986.

Image options

John Ahlrichs, agriculture market director for DigitalGlobe, says the type of image a farmer chooses depends on how much resolution is required. Depending on the grower's needs, his company can offer products derived from high-, medium- and low-resolution photos.

Ahlrichs explains that Landsat images are best for showing large areas, with each pixel typically representing a 90- × 90-ft. area. Spot is for medium-resolution imagery at a 30- to 60-ft. resolution, and QuickBird images can offer 2-ft. resolution in black and white or 8-ft. resolution in color.

“At 2-ft. resolution, you can see individual trees or rows of vines,” Ahlrichs says. “That's valuable for orchards and vineyards, but it isn't something most row-crop producers need. With the right software, a corn and soybean grower can get most of the information needed from a Spot or sometimes a Landsat photo.”

Change detection

Ahlrichs says satellite imagery wasn't a useful tool for farmers in the past because nobody really focused on the real-time needs of the ag market.

“Farmers could get images, but they were two months old,” Ahlrichs says. “That's just not timely enough for an agricultural business. We can now get medium-resolution data posted within two or three days of when it was collected. QuickBird imagery with its 2-ft. resolution takes about a week. That's fast enough to see crop health changes and the effects of actions the farmer has taken in the field.”

The second big advance developed by DigitalGlobe has been image calibration. “To accurately detect changes in crop health, color and index values need to be the same from one photo to the next,” Ahlrichs explains. “Using an uncalibrated image would be similar to soil testing with an uncalibrated pH meter — not very useful.”

Ahlrichs explains that data consistency is also a matter of eliminating background clutter with the right analysis methods. “It just took one of our staff with a new way to look at an old problem to come up with the right algorithms,” he says. “Now that we have the programs in place, we can produce image products that are clean, reliable and repeatable.”

By gauging visual changes in crop vegetation, DigitalGlobe's AgroWatch products aim to help farmers take advantage of precision variable-rate technology. The Green Vegetation Index allows quicker quantitative scouting. The AgroWatch soil zone map can show the influence of surface soil characteristics on vegetation health and where to sample. Another product, ScoutAide, shows the absolute amount of vegetation change, helping identify problem areas where the crop is changing faster than expected or validating the result of changing production practices.

Competitive companies

Perhaps the best evidence that DigitalGlobe may be on to something big is the fact that competitors already are lining up to grab business.

Even Cannon Michael, who was impressed with the results and service he got from DigitalGlobe, hasn't hesitated to look at using the services of other imaging companies.

“After talking to several companies, we realized satellite images might be a good alternative to soil grid sampling,” Michael says. “But since that function doesn't require fast turnaround or high resolution, we went with a lower-cost service out of Fresno, CA, called Smart Image. The company interprets government Landsat images. For $4,000, we get six photos of our farm taken at different times throughout the summer.”

Grid sampling alternative

Michael says the results are worth it. “We went out in the fields with a GPS receiver to ‘ground truth’ the images and were impressed with how accurate the photos really are at showing variations in crop health within a field,” he says. “Now, we're very comfortable in trusting the images.”

Rather than grid sampling a whole field, Michael can now look at where the crop variations are and selectively soil sample to see what nutrients or soil amendments are needed. “It's a more accurate and intelligent way to soil sample than a one-acre grid, and the total cost, including the satellite photos, is less than 60% of grid sampling,” he says.

Agribusiness revolution?

Despite the tantalizing potential and success stories of early adopters such as Michael, the market for agricultural satellite imagery is still young and largely unproven. A lot will depend on the technology, how it is marketed and how the competition shakes out. While DigitalGlobe's QuickBird satellite and branded products give the company some claim to a market leadership position now, small services such as Smart Image could fill an important niche too. Meanwhile, a Denver-based image data provider called Resource21 hopes to vie for leadership in the near future.

After 12 years of research and development, Resource21 recently announced the launch of its new AgriTrax suite of image products. Jointly owned by The Boeing Company, BAE Systems, Farmland Industries, and the Institute for Technology Development, Resource21 uses satellite imagery and analysis to provide ag retailers and their grower customers with precise, accurate and affordable information about how crops are performing in field.

Generally priced from $1 to $3/acre, AgriTrax products are sold through certified retailers throughout the U.S. and Australia. The AgriTrax line includes customized products for site-specific yield estimation, nitrogen management and cotton growth management. Products are currently available for all crops.

Dennis Dunivan, vice president of the agricultural business for Resource21, explains the company's sales strategy. “I expect many retailers will resell our images as part of a complete precision management package that will let growers keep their crops on track in several areas, including nutrient management, yield tracking and growth management,” he says.

Springboard to success

Dunivan says his company's big break could come if Resource21 wins a pending government contract for the Landsat Data Continuity Mission, a program to replace the aging Landsat 7 system in 2006. The credibility gained and the infusion of hundreds of millions of dollars in government funds could make Resource21 extremely competitive in the ag market.

Dunivan likes his company's chances of winning. “If Resource21 is awarded the Landsat contract, it would literally revolutionize satellite imaging for agribusiness,” he claims. “The next generation will allow a 10-meter resolution. That's important because affordable 10-meter resolution makes it possible to easily and accurately identify field boundaries and isolate crop conditions within a field. When you can look at an image and see the boundary of each field, it immediately makes the image more useful. It allows imagery to become a critical component that will drive the value of precision agriculture.”

Whirlybirds and RC airplanes

Remote sensing alternatives seem limited only by the imagination. Options range from the simple — an infrared camera on a kite or a long pole that a farmer can hold over his head while he walks through fields — to James Bond-inspired gadgets mounted on remote-controlled aircraft.

The Illinois Laboratory for Agricultural Remote Sensing, for example, is using a 4- × 3-ft. remote-controlled helicopter to generate maps for precision agriculture. It's not as goofy as it sounds.

A camera, mounted on the front of the helicopter, takes color and infrared field-map images, says Lei Tian, a University of Illinois agricultural engineer.

Tian says farmers can use these maps to determine nitrogen stress or weed pressure on crops so that application equipment can automatically vary chemicals according to field needs. As a result, farmers save money by using the chemicals more accurately.

“Precision farming was really hot in the nineties, but lately it has cooled down,” Tian says. “One of the reasons is that the sensing systems weren't advanced enough yet to create good maps of the fields.”

Before Tian and his colleagues used the miniature helicopter, they relied on satellite images and aerial images taken from planes to create maps. But the drawback was that the image delivery depended upon weather conditions and other uncontrollable factors.

In addition, Tian says, because timing is critical when studying nitrogen stress or weed infestations, researchers could not rely on satellite or airplane images that were generated days, even weeks, before or after the data should have been collected.

The advantage of using a remote-controlled helicopter is flexibility, Tian says. The researchers can take pictures anytime throughout the growing season.

Presently, Tian is working on an autopilot system for the helicopter, but for now two people pilot the unmanned vehicle. One person controls the helicopter, and the other person controls the camera.

The autopilot will be a one-button system, he adds. The operator will simply press the button and the autopilot will do the rest.

Once the system is refined, Tian envisions companies someday using such equipment to scout fields and create aerial maps for farmers. Who knows? Perhaps satellite image archives and remote-controlled helicopters will one day become standard equipment for the crop consultants who visit your farm.

You can order the book A Farmer's Guide to Remote Sensing for $25 (includes shipping and handling) by calling 515/251-8640, visiting www.iasoybeans.com, or mailing your order to Iowa Soybean Association, 4554 N.W. 114th St., Urbandale, IA 50322-5410.